Regular Late Trades

Gday All
Was just wondering if someone may be able to answer a question I have. On regular occasions/multiple trading days (it seems it is always around 10 minutes and a few seconds after the market close), trades go through on this share which go through to bring the value of the stock down by $0.001 each time. I was watching ETrade on Friday where after the market close, the market depth on ETrade showed the lowest seller was offering at I believe $0.046 and I think the highest buyer had a price of $0.055 or something similar. This was at just after 1.10pm WA time. I then refreshed my screen and a final buy went through at $0.044 (time was 4.10pm and a few seconds) after the price had been at $0.045 for quite a while. The seller's and buyer's prices/number of shares on the market depth also appeared to not change. Then again today after what appeared to be the market close, a trade goes through for $0.041 after the price was at $0.042 for a while. I can recall this same thing occurring fairly regularly and was wondering why it's happening as I thought all trades ceased at the market close which is 4.00pm Eastern States time (I'm in WA). If someone can shed some light on it for me, this would be very much appreciated. Many thanks.